Question

question 9 refers to the following drawing.

1. linda adds a water stabilizer to her chil-

drens swimming pool once a week. the
instructions tell her to add one scoop
of the product for every 20 cubic feet of
water. about how many scoops should
she add per week?
a. 3
b. 6
c. 17
d. 36

Explanation:

Step1: Calculate the volume of the pool

The pool is a cylinder. The formula for the volume of a cylinder is \(V=\pi r^{2}h\). Given the diameter \(d = 12\) ft, so the radius \(r=\frac{d}{2}=\frac{12}{2}=6\) ft and the height \(h = 3\) ft. Then \(V=\pi\times6^{2}\times3=\pi\times36\times3 = 108\pi\approx108\times3.14 = 339.12\) cubic feet.

Step2: Calculate the number of scoops

Since one scoop is for every 20 cubic feet of water. The number of scoops \(n=\frac{V}{20}\). Substitute \(V = 339.12\) into the formula, \(n=\frac{339.12}{20}=16.956\approx17\).

Answer:

C. 17